Marine Power (Chevy 350) Operating Temps (another one)-gctid386281

[Guest]

OK help me feel good or bad about this:

My Bayliner COntessa FB is set up with a MP350 (higher HP model). Runs great but noticed a little tick up in engine temp when cruising hard.

At idle and after warm-up (engine commonly spikes at ~175 before dropping) engine temp is 150to 155 (right below 160 marker or mid point between 140 and 160). She's up and running on plane she might inch up to 160 or just under. Nearer to WOT or 85% of WOT she is closer to probably 162-165 maybe a tad higher. Never approaches 180 and the temp remains stable while running at whatever speed.

Forgot to check riser/manifolds temp by hand last time out but she was still mildly warm 1/2 hour after returning to dock..no wierd smells or anything.

Impeller replaced last year (even 3 yo impeller that was replaced was good as new). Risers/maniforlds replaced 3 years ago.

Any concerns here? I just dont recall that change in engine temp (except when belts were loose ..which they are not right now).

[Guest]

Sounds perfect to me!

[Chief_Alen]

Your golden just enjoy

[yachtman]

I have a marine power manual at home. Illl check it oit later today. Do you have closed or raw water cooled engine?

[Guest]

yachtman wrote:
I have a marine power manual at home. Illl check it oit later today. Do you have closed or raw water cooled engine?

It is a closed system (coolant/heat exchanger)

Im betting its all within specs my concern is why can't system keep temp level at idle/low load levels? Betting something must be failing..or...maybe boat was not working right before haha.

[yachtman]

Here is a pic of the manual. Closed system uses a 160┬░thermostat. It shouldnt vary more than 10┬░ either way

[img]/media/kunena/attachments/vb/689934=28219-2012-05-29_17-55-41_619.jpg[/img]

[yachtman]

[img]/media/kunena/attachments/vb/689975=28229-2012-05-29_19-37-53_574.jpg[/img]I found this in the manual also. I can tell.you from experience that if your engines are running at or above 180┬░at normal cruise when you go to push it it will most likely over heat. Mine ran at 165-170┬░. Now keep in mind every engine and guage are different.

[2850Bounty]

The different readings may be a result of a bad temp sender. This is an easy and inexpensive part to replace.

NOTE: the temperature sending unit for dual stations is not same as single station.

Install with thread sealant, no teflon tape.

[Guest]

Mine runs spot on 175 all day. You're fine.

[Guest]

Ok I feel a little better. Still not sure why it varies so much (as it never used to) Ill trade out sending unit and see what happens.

[Guest]

http://www.boatfix.com/how/cooling.html

[Guest]

sea-cruisier wrote:
OK help me feel good or bad about this:

My Bayliner COntessa FB is set up with a MP350 (higher HP model). Runs great but noticed a little tick up in engine temp when cruising hard.

At idle and after warm-up (engine commonly spikes at ~175 before dropping) engine temp is 150to 155 (right below 160 marker or mid point between 140 and 160). She's up and running on plane she might inch up to 160 or just under. Nearer to WOT or 85% of WOT she is closer to probably 162-165 maybe a tad higher. Never approaches 180 and the temp remains stable while running at whatever speed.

Forgot to check riser/manifolds temp by hand last time out but she was still mildly warm 1/2 hour after returning to dock..no wierd smells or anything.

Impeller replaced last year (even 3 yo impeller that was replaced was good as new). Risers/maniforlds replaced 3 years ago.

Any concerns here? I just dont recall that change in engine temp (except when belts were loose ..which they are not right now).

Sea Cruiser: Both of my 250 HP 350's indicate a little over 170, but their accuracy is questionable. Sure runs fine!! Griff

[2850Bounty]

Sea Cruiser, you mention Bayliner Contessa F/B, but no mention of which year nor which drive.

The Marine Power 5.7L SBC found it's way into many Volvo Penta drive applications years ago.

If your boat is mid 80's (up through '86), and is equipped with the V/P out drive, you'll want to know several things regarding a few components within the sea water path from the drive to the engine mounted sea water pump.

If not V/P...... pardon my interruption, and carry on here!

.

[Guest]

I had some issues with a temp sender (sensor) on one of my engines. See if you can get a infa-red thermometer and shoot the engine heads and manifolds when you are running. This will confirm your readings.

My senders were off by about 10 and 20 deg. No problem. I'm looking for a change, indicating an operating problem, so I just marked the guage at the normal operating position, and I look for changes to indicate an issue.

Chay

[Guest]

2850Bounty wrote:
Sea Cruiser, you mention Bayliner Contessa F/B, but no mention of which year nor which drive.

The Marine Power 5.7L SBC found it's way into many Volvo Penta drive applications years ago.

If your boat is mid 80's (up through '86), and is equipped with the V/P out drive, you'll want to know several things regarding a few components within the sea water path from the drive to the engine mounted sea water pump.

If not V/P...... pardon my interruption, and carry on here!

.

Its a '84. Think I have the origninal Volvo upper unit with a DP lower unit. Running B2s for what its worth.

Let me know your thoughts on this. Had this boat for long enought to believe something is not quite right IMO (7 years 600+ hours) . Any thoughts on how to check the cooling /exhaust system would be great. Thinking of having someone out to check it out but am up for any quick hit trouble shooting steps that can be performed with boat in water by me to save some $.

Thanks Rick!

BTW- used to have all that info in my profile...wonder where it went?